Add the ability to setup OT&E from the web console

We create a new endpoint with a simple form that will let admins (including
support) setup OT&E for registrars.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=226570568

java/google/registry/env/common/default/WEB-INF/web.xml

@@ -37,6 +37,12 @@
     <url-pattern>/registrar-settings</url-pattern>
   </servlet-mapping>
 
+  <!-- OT&E creation console. -->
+  <servlet-mapping>
+    <servlet-name>frontend-servlet</servlet-name>
+    <url-pattern>/registrar-ote-setup</url-pattern>
+  </servlet-mapping>
+
   <!-- Security config -->
   <security-constraint>
     <web-resource-collection>